Today i did a brief interview with E-TV news on "Anonymity Systems". Interestingly enough, the journalist started the interview determined to go down the "Anonymity is Evil!" route.
I must confess to being slightly surprised by the thought. I didn't expect such strong support for the "Anonymity allows Child Pornography" point of view. The snippet of the interview that was aired was probably only a few minutes long (I have not seen it yet), but i thought it was probably worth it to note a few simple thoughts on Anonymity systems.
Very few people, (if any), would question the necessity of allowing anonymity for people who suffer from victimization. Dissidents of a tyrannical regime, or victims of crime need a platform that will permit them to speak out without fear of further victimization. The problem is that "anonymity needs company".
This simply implies that it's really difficult to be anonymous alone.
Signals Intelligence operators have long established that merely knowing that Alice spoke to Bob is worth a lot, even if we are unable to examine the content of their discussion. If the only people using an anonymity system are government dissidents, then finding the dissidents is as simple as rounding up the people using anonymity systems. For the system to work, we need people using the system beyond simply those who today "have something to hide." 
A natural side-effect of providing an Anonymizing system, is that this system will also be used for evil. (It is very much like) A side effect of us being able to have encrypted conversations is that terrorists can have conversations that can't easily be intercepted by law enforcement. It's ridiculous to deny the privacy benefit to everyone, in the hope of maybe helping to catch a few criminals. Terrorists have no problem finding other channels of communication that are less susceptible to interception. Forbidding crypto hurts the rest of us. Viewers of kiddie-porn are able to share their wares without anonymity systems. Stopping online anonymity wont slow them down at all..
Convincing people who think "they have nothing to hide", that anonymity (and encryption) are good things is sometimes difficult, but recent events should convince most that even governments we elect into power, might not always have our best interests at heart. It's probably over used, but one is forced to remember the words of Pastor Niemöller, who commented on the inactivity of German intellectuals during the Nazi rise to power:
"They came first for the Communists,
and I didn't speak up because I wasn't a Communist.
Then they came for the trade unionists,
and I didn't speak up because I wasn't a trade unionist.
Then they came for the Jews,
and I didn't speak up because I wasn't a Jew.
Then they came for me
and by that time no one was left to speak up."
 It is interesting to note, that some governments who say "You don't need anonymity unless you have something to hide" are the same people who feel outraged by WikiLeaks.